Seal of a vertical pump

ABSTRACT

A seal of a vertical pump mainly has a front casing disposed fixedly and forwardly on a main casing which has a motor disposed therein; a volute chamber is disposed inside the front casing for placing a centrifugal impeller; an suction inlet is disposed axially and forwardly on the front casing opposite to the motor; a water outlet is disposed upwardly thereon and opposite the lateral side of the impeller to engage with an discharge pipe; the suction inlet and outlet are communicated with a volute chamber. The present invention is characterized that a non-contact seal is disposed on the front rim of a cantilever shaft; the seal does jam when a liquid crystallizes. Therefore, no heat generates due to the friction of the seal thereby preventing the stopping and sealing of the pump. Furthermore, it also prevents a back impeller vane from stirring the air and spitting out the liquid with a lot of air bubbles when the pump operates. Therefore, it eliminates the air bubbles from causing serious and undesired influence during the manufacturing process of a printed circuit board.

BACKGROUND OF THE INVENTION

[0001] 1.) Field of the Invention

[0002] The present invention relates to a seal of a vertical pump, more particularly to a structure having a non-contact and improved seal of a traditional labyrinth seal disposed on a front rim of a cantilever shaft.

[0003] 2.) Description of the Prior Art

[0004] Accordingly, as indicated in FIGS. 1 and 2, a regular and traditional pump is used at a chemical engineering site for pumping and delivering strong acid, alkali and corrosive liquid. A cantilever shaft (200) disposed at the front end of a motor (100); a V-type oil seal (300) or a lip seal is disposed near the tail end of the cantilever shaft (200). The main purpose of the seal device is to block the acid and alkali liquid because the V-type oil seal (300) becomes ineffective once it contacts the liquid, especially the crystallizable liquid. That might further corrode an axle center of the motor (100). The front end of the cantilever shaft (200) vertically connects with an axle center of an impeller (400); the backside of the impeller (400) is disposed with a back vane (401). In addition, a front casing (500) is inserted forwardly on a main casing; a suction inlet (500) is disposed axially and forwardly on the front casing (500) opposite the motor (100); a water outlet (502) is disposed upwardly thereon opposite the lateral side of the impeller (400) to engage with an discharge pipe (600). The suction inlet (501) and the water outlet (502) are communicated with a volute chamber (700). In an actual implementation, a liquid flows axially from the axial suction inlet (700) toward the impeller (400) which rotates to work; the volute chamber (700) gathers the liquid with high pressure and conducts it outwardly from the water outlet (502). However, the conventional vertical pump has two shortcomings:

[0005] 1. It uses the back vane (401) to eliminate the back pressure of the impeller (400). However, the back vane (401) stirs the air and the delivery liquid to mix with a lot of air bubbles; the air bubbles tremendously increase the undesired rate during the manufacturing process of a printed circuit board.

[0006] 2. When the pump stops and the back vane (401) is not working, the liquid dashes reversely to the V-type seal (300) above the liquid surface in a similar water hammer effect; if the liquid left on the seal device crystallizes, it damages the V-type seal (300) device or the lip seal. Although some manufacturers suggested the use of a check valve for solving this problem, most of the machines do not have enough space for installation and plus, the crystallization might make the check valve inefficient.

SUMMARY OF THE INVENTION

[0007] Therefore, the primary objective of the present invention is to dispose a non-contact seal on a front rim of a cantilever shaft of a vertical pump to prevent a back vane from stirring the air and causing the pump to spit out a liquid with a lot of bubbles so as to eliminate the air bubbles from causing any serious undesired effect during the manufacturing process of a printed circuit board.

[0008] Another objective of the present invention is to dispose the non-contact seal as a non-contact labyrinth seal so as to prevent the liquid crystallization which might seals or jams the seal and to eliminate the heat generation due to the friction of the seal.

[0009] To enable a further understanding of the structural features and the technical contents of the present invention, the brief description of the drawings below is followed by the detailed description of the preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a cross-sectional drawing of a conventional product.

[0011]FIG. 2 is a cross-sectional drawing of a part of the conventional product.

[0012]FIG. 3 is a cross-sectional drawing of the present invention.

[0013]FIG. 4 is a cross-sectional drawing of a part of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] As indicated in FIGS. 3 and 4, the present invention of a vertical pump comprises a front casing (4) disposed fixedly and forwardly on a main casing which has a motor (1) disposed therein; a cantilever shaft (2) of the motor (1) is located toward the front casing (1); a volute chamber (6) is disposed inside the front casing (4) for placing a centrifugal impeller (3); an suction inlet (41) is disposed axially and forwardly on the front casing (4) opposite to the motor (1); a water outlet (42) is disposed upwardly thereon and opposite the lateral side of the impeller (3) to engage with an discharge pipe (5); both of the suction inlet (41) and the water outlet (42) are communicated with the volute chamber (6). The V-type oil seal (7) device axially connects onto the cantilever shaft (2) near the motor (1). The present invention is mainly characterized that a non-contact seal (8) is disposed on the front rim of a cantilever shaft (2). The functions of the non-contact seal (8) of the present invention are as follows:

[0015] 1. It prevents a back impeller vane from stirring the air and spitting out the liquid with a lot of air bubbles when the pump operates. Therefore, it eliminates the air bubbles from causing serious and undesired influence during the manufacturing process of a printed circuit board.

[0016] 2. It prevents the acid and alkali liquid dashes reversely to the V-type oil seal (7) device located above the liquid surface when the pump stops and the pressure fails to be discharged in time.

[0017] 3. The non-contact seal (8) is of a non-contact labyrinth seal. Therefore, it prevents the possibility of having the seal (8) been stuck or jammed due to liquid crystallization and the possibility of heat generation due to the friction of the seal.

[0018] In summation of the abovementioned, the present invention comprising a non-contact seal (8) disposed on the front rim of the cantilever shaft (2) to not only prevent the heat from being generated by the friction due to the stuck and jam caused by the liquid crystallization, but also prevent the liquid from dashing reversely toward the V-type oil seal when the pump stops and the pressure fails to be discharged in time. Mostly, the non-contact seal (8) is capable of eliminating the back vane from stirring the air to make the pump spitting out the liquid with a lot of air bubbles thereby preventing the air bubbles from causing serious and undesired influence during the manufacturing process of a printed circuit board.

[0019] It is of course to be understood that the embodiment described herein is merely illustrative of the principles of the invention and that a wide variety of modifications thereto may be effected by persons skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims. 

1. A seal of a vertical pump comprises a front casing disposed fixedly and forwardly on a main casing which has a motor disposed therein; a cantilever shaft of the motor is located toward the front casing; a volute chamber is disposed inside the front casing for placing a centrifugal impeller ; an suction inlet is disposed axially and forwardly on the front casing opposite to the motor; a water outlet is disposed upwardly thereon and opposite the lateral side of the impeller to engage with an discharge pipe; both of the suction inlet and the water outlet are communicated with the volute chamber; the present invention is mainly characterized that: a non-contact seal is disposed on the front rim of the cantilever shaft to not only prevent the acid and alkali liquid from dashing reversely toward the V-type oil seal located above the liquid surface when the pump stops and the pressure fails to be discharged in time, but also prevent a back vane from stirring the air to cause the pump to spit out the liquid with a lot of bubbles.
 2. The seal of a vertical pump according to claim 1, wherein the noncontact seal is of an improved traditional labyrinth seal. 